Percy Julian, Robert Robinson, and the Identity of EseretholeAddison AultThe Nova production Percy JulianForgotten Genius, which included the very public disagreement over the identity of "eserethole," the key intermediate for the synthesis of the alkaloid physostigmine, left three important chemical questions unanswered.Ault, Addison. J. Chem. Educ.2008, 85, 1524.

Constitutional Isomers |

Enantiomers |

Natural Products |

Stereochemistry |

Synthesis

A Green, Guided-Inquiry Based Electrophilic Aromatic Substitution for the Organic Chemistry LaboratoryEric Eby and S. Todd DealThis alternative, electrophilic aromatic substitutionan iodination reaction of salicylamide, a popular analgesicuses environmentally friendly reagents and serves as a guided-inquiry experiment in which students are asked to predict the orientation of the substitution reaction and determine the product's structure using FT-IR spectroscopy.Eby, Eric; Deal, S. Todd. J. Chem. Educ.2008, 85, 1426.

Aromatic Compounds |

Constitutional Isomers |

Electrophilic Substitution |

Green Chemistry |

IR Spectroscopy |

Synthesis

The Iodochlorination of Styrene: An Experiment That Makes a DifferenceR. Gary Amiet and Sylvia UrbanThis purpose of this laboratory exercise is to determine the various substitution and elimination products generated in the iodochlorination of styrene and their relative proportions through the application of mechanistic principles and a basic knowledge of GCMS and NMR.Amiet, R. Gary; Urban, Sylvia. J. Chem. Educ.2008, 85, 962.

Alkenes |

Constitutional Isomers |

Gas Chromatography |

Instrumental Methods |

Mass Spectrometry |

Mechanisms of Reactions |

NMR Spectroscopy |

Synthesis |

Student-Centered Learning

A Nitration Reaction Puzzle for the Organic Chemistry LaboratoryMilton J. Wieder and Russell BarrowsTreatment of phenylacetic acid with different concentrations of nitric acid yields two different products. Using 1H NMR and IR spectral data, students are asked to deduce the structures of the two products, thus illustrating fundamental concepts in electrophilic aromatic substitution while posing an interesting structure elucidation puzzle.Wieder, Milton J.; Barrows, Russell. J. Chem. Educ.2008, 85, 549.

Constitutional Isomers |

Mass Spectrometry |

NMR Spectroscopy |

Synthesis |

Titration / Volumetric Analysis

Regioselectivity in Organic Synthesis: Preparation of the Bromohydrin of α-MethylstyreneBrad Andersh, Kathryn N. Kilby, Meghan E. Turnis, and Drew L. MurphyIn the described experiment, the regiochemical outcome of the addition of "HOBr" to a-methylstyrene is investigated. Although both "classic" qualitative analysis and instrumental techniques are described, the emphasis of this experiment is on the utilization 13C and DEPT-135 NMR spectroscopy to determine the regiochemical outcome of the addition. Andersh, Brad; Kilby, Kathryn N.; Turnis, Meghan E.; Murphy, Drew L. J. Chem. Educ.2008, 85, 102.

Discovering Electronic Effects of Substituents in Nitrations of Benzene Derivatives Using GC–MS AnalysisMalgorzata M. Clennan and Edward L. ClennanDescribes an organic lab in which students pool mass spectral data to identify the distribution of isomer products generated by the nitration of six benzene derivatives whose substituents differ in their electronic effects. Students also determine which substituents direct nitration predominantly to the ortho- or para- and to the meta positions.Clennan, Malgorzata M.; Clennan, Edward L. J. Chem. Educ.2007, 84, 1679.

Conversion of an Aziridine to an Oxazolidinone Using a Salt and Carbon Dioxide in WaterJustin R. Wallace, Deborah L. Lieberman, Matthew T. Hancock, and Allan R. PinhasAn undergraduate laboratory experiment that allows for optimization of experimental reaction conditions for the conversion of a readily-available aziridine to the corresponding oxazolidinone using only carbon dioxide and a salt in water is discussed. A variety of salts were used to determine their effect on the reaction. In all cases, either no reaction occurred or a high yield of product was obtained. Ring opening of the less substituted carbonnitrogen bond predominates. This experiment allows students to optimize reaction conditions to obtain predominantly one of two regioisomers. Wallace, Justin R.; Lieberman, Deborah L.; Hancock, Matthew T.; Pinhas, Allan R. J. Chem. Educ.2005, 82, 1229.

Heterocycles |

Synthesis |

Aqueous Solution Chemistry |

Constitutional Isomers |

Mechanisms of Reactions |

NMR Spectroscopy |

Quantitative Analysis

Testing for Genetically Modified Foods Using PCRAnn Taylor and Samin SajanThe polymerase chain reaction (PCR) is a powerful technique used to detect and amplify a specific DNA sequence. In this experiment, DNA is isolated from commercially available corn meal and corn-muffin mixes, then a sequence unique to transgenic plants is amplified by PCR. The amplified sequence is identified by its size (192 base pairs) by agarose gel electrophoresis. This experiment could be used in either a biochemistry course or in an analytical chemistry course in a curriculum that integrates biochemistry throughout the course work. Taylor, Ann; Sajan, Samin. J. Chem. Educ.2005, 82, 597.

Agricultural Chemistry |

Constitutional Isomers |

Biotechnology |

Plant Chemistry |

Consumer Chemistry |

Nucleic Acids / DNA / RNA

A Set of Hands-On Exercises on Conformational AnalysisSilvina C. Pellegrinet and Ernesto G. MataThis article describes a set of comprehensive exercises on conformational analysis that employs a hands-on approach by the use of molecular modeling kits. In addition, the exercises provide illustrations of other topics such as nomenclature, functional groups, and isomerism, and introduce some notions of chirality. Pellegrinet, Silvina C.; Mata, Ernesto G. J. Chem. Educ.2005, 82, 73.

Alkanes / Cycloalkanes |

Conformational Analysis |

Constitutional Isomers |

Molecular Properties / Structure |

Stereochemistry

Studying Current–Potential Curves Using Bipotentiometric Iodometric Back-Titration for the Determination of Ascorbic Acid in Fruits and VegetablesRoxana A. Verdini and Claudia M. LagierA method for the determination of the ascorbic acid content in fruits and vegetables was used to introduce the principles of voltammetry. The procedure combines an iodometric back-titration with voltammetric (bipotentiometric) end point detection, which minimizes the risk of ascorbic acid oxidation, allowing for a rapid and efficient quantification of vitamin C in fruits and vegetables. A better understanding of the titration curve is achieved by analyzing the schematic currentpotential curves of the anodic and cathodic half-cell reactions during the titration. Verdini, Roxana A.; Lagier, Claudia M. J. Chem. Educ.2004, 81, 1482.

The diverse nature of the C6H6 moleculePotgeiter, J. H.The purpose of this discussion is to show that C6H6 describes more than just one kind of benzene.Potgeiter, J. H. J. Chem. Educ.1991, 68, 280.

Aromatic Compounds |

Alkenes |

Reactions |

Constitutional Isomers

Representing isomeric structuresThall, Edwin"Representing isomeric structures" is the name of a technique this author has developed to help students learn to draw molecular structures of isomers in their first organic chemistry class.Thall, Edwin J. Chem. Educ.1991, 68, 190.

Constitutional Isomers |

Diastereomers

Stereochemistry of cyclic hydrocarbons Perkins, Robert R.The topic of stereochemistry always poses great difficulties for many students in introductory organic chemistry. The following problems can be used as a tutorial question after having introduced the various terms associated with stereochemistry. The question requires skills at the applications level in the Bloom taxonomy.Perkins, Robert R. J. Chem. Educ.1988, 65, 860.

Stereospecific thermal cycloadditions and catalyzed isomerizations: An organic laboratory projectPasto, D. J.; Duncan, J. A.; Silversmith, E. F.The authors have prepared a sequence of experiments for their undergraduate organic chemistry laboratory concerned with the preparation of cis and trans 1,4-diphenyl-2-butene-1,4diones, their cycloadditions reactions with cyclopentandiene, and with related isomerization reactions of both the sequence, which has met with much success experimentally, clearly and collectively demonstrates certain aspects of the concepts of thermodynamics, kinetics, and stereochemistry and photochemistry.Pasto, D. J.; Duncan, J. A.; Silversmith, E. F. J. Chem. Educ.1974, 51, 277.

Photochemistry |

Constitutional Isomers |

Addition Reactions

A laboratory study of strike and inductive effectsFulkrod, John E.The authors describe a general reaction that can be successfully used to teach both strike and inductive effects in the laboratory by discovery.Fulkrod, John E. J. Chem. Educ.1974, 51, 115.

Potentialities of protein isomerismAsimov, IsaacThe permutations generated by structural isomerism in proteins could be demonstrated more convincingly and realistically if the amino acid compositions of actual proteins were taken into consideration.Asimov, Isaac J. Chem. Educ.1954, 31, 125.